a) Field of the Invention
This invention relates to a new or improved wear protector system, and in particular to a replaceable assembly for protecting from wear the leading edge of an earthmoving implement such as a drag line bucket, a face shovel, buckets for front-end loaders, excavators and the like.
b) Description of the Prior Art
It has long been recognized that measures must be taken to protect the leading edge of earthmoving implements against wear. Typically these leading edges include a series of laterally spaced hardened digging teeth, and the sections of the leading edge between these teeth, if not protected are subject to rapid wear as a result of the abrasive environment in which the implement typically operates. The problems resulting from this wear can be reduced through the use of wear parts or shrouds designed to shield the leading edge, but provision must be made for securing such shrouds to the implement in a manner that reliably fastens them during operation yet allows for their easy removal and replacement when they become worn. Such shrouds are required to have high resistance to impact and to abrasion wear and are made of steel alloys which provide these properties. However such materials are not compatible with normal weld procedures and therefore the shrouds cannot be welded directly to the implement, e.g. a bucket lip. Mechanical fastening systems involving the provisions of holes through the bucket lip are undesirable because of the weakening effect of such holes. Accordingly it is known to provide a mounting system incorporating a mounting block or boss of a weldable steel which is welded to the bucket lip and to provide a mechanical attachment means for anchoring the shroud to the block. Examples of such wear protection systems can be seen in U.S. Pat. No. 5,088,214 Jones and U.S. Pat. No. 4,748,754 Schwappach.
The present invention provides a wear protector system for shielding from wear a portion of a leading edge of an earthmoving implement, said system including; an anchor for fixed welded attachment to a surface of said implement at a predetermined location rearwardly of said leading edge, said anchor comprising a block having a bottom surface for attachment to said implement surface, an undercut transverse forward first abutment surface, and an upper surface; and a shroud having a U-shaped nose and a rearwardly extending tail, said tail defining a transverse rearwardly facing second abutment surface that is complementary to said first abutment surface, said anchor and said shroud being configured to interengage when said anchor is fixed to the implement at said location such that the nose of the shroud lies against and extends around said leading edge; said anchor and said shroud having respective complementary channels, which, when said anchor and shroud are interengaged, together define a transverse passageway through which a tapered cotter pin can be inserted to retain said shroud in engagement with said anchor and with the leading edge of the implement. The complementary channels are mutually offset in the front-to-rear direction so that the cotter pin when engaged will urge the shroud rearwardly with a wedging action.
The first abutment surface is preferably undercut by being inclined rearwardly from top-to-bottom, the mating abutment surface on the shroud being similarly inclined, this undercut configuration being effective to prevent the tail of the shroud rising out of contact with the anchor. Additional pairs of abutment surfaces may be provided to reinforce this effect, and preferably each abutment surface comprises a pair of facets that are angled to opposite sides forwardly or rearwardly with respect of the transverse direction to provide a centering effect of the shroud relative to the anchor.
The profile of the cotter pin is preferably tapered along its length so that it can be driven in to the transverse passageway to varying degrees, and thus the arrangement, together with the offset in the channels of the shroud and the anchor, is capable of taking up any clearance that may arise in the mounting system as a result of wear during extended periods of service. Preferably the passageway is tapered from opposite sides towards its central area so that the cotter pin can be driven in from either side. To prevent accidental dislodgement of the cotter pin, preferably it is of a length sufficient that its leading end extends completely through the passageway and can be swaged over, this deformation preventing accidental withdrawal.